(96i) Guided Motion of Self-Propelled Magnetic Colloidal Particles by Brownian Dynamics Simulations

Authors: 
Vidal, G., University of Puerto Rico at Mayagüez
Rinaldi, C., University of Puerto Rico at Mayagüez
Córdova-Figueroa, U. M., University of Puerto Rico at Mayagüez


Self-propulsion of artificial nano- and microscale objects by the transformation of chemical energy into motion is one of the most fascinating and exciting challenges currently studied. It has been shown in recent experiments that autonomous motion of the so-called ?catalytic' motors is hindered by their rotary Brownian motion and thus preventing its potential to be fully realized. However, such limitation could be relaxed with colloidal particles sensitive to external magnetic fields. The present study investigates the short and long-time diffusive behavior of a catalytically driven ?magnetic' colloidal particle immersed in a dispersion of reactant particles subject to a magnetic field using Brownian dynamics simulations. The strength of the magnetic field is controlled by the Langevin parameter, which physically measures the relative importance of magnetic to Brownian torques, and dictates the spatiotemporal behavior of the particle. The translational self-diffusivity is measured for different surface reaction speeds, particle sizes, reactant particle concentrations, magnetic dipole orientations, and Langevin parameters. Finally, a theory to determine the long-time self-diffusivity and time-averaged particle velocity is constructed and compared to the simulation results.